Part of a field glass



FIG. 1 is a left side elevational view of a part of a field glass showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a perspective view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a rear elevational view thereof.

The broken line immediately adjacent the shaded area represents the bounds of claimed design while all other broken lines are directed to environment and form no part of the claimed design. 

The ornamental design for a part of a field glass, as shown and described. 